The message, on the face of it, was familiar. A warning of the potential pitfalls that supposedly lie in wait for business in the event of Scottish independence.

However, the tone was discernibly different. To be quite clear, Vince Cable had returned to Glasgow - where he was formerly a student, a lecturer and a Labour councillor - to posit the values of the Union. The UK? He's for it.

The other aspect was shadowy, adumbrated. But, still, it was there. For example, Dr Cable seemed to mean it when he talked of independence having an upside and a downside. (He believed the downside to be considerably larger in scale.)

To be clear, others in the queue of UK Ministers heading to Scotland have stressed that Scottish independence is feasible. But they have sometimes done so in a manner suggesting that such a step would be palpable folly, rather than a balanced choice.

Dr Cable's tone - again, it is tone - was different. In which regard, another thought. The report he was launching suggests that, post independence, consumers in England might be inclined to alter their preferences and turn away, to some extent, from purchasing goods with an evident Scottish branding or association.

When and what?

Scottish independence referendum - The electorate in Scotland will go to the polls on Thursday, 18 September, 2014

The question - Voters will be asked the yes/no questions: "Should Scotland be an independent country?"

In the course of an interview, I questioned Dr Cable more than once about that point, inviting him to justify it or expand upon it. He repeatedly, politely declined. Not, plainly, an avenue he wished to pursue.

His declared intent was to accentuate the positive, to focus upon the advantages which he perceived in the UK single market, as he described it, rather than to spotlight the anxieties about independence which - again, let us be clear - form a substantial part of the report launched today by his Business department in the UK Government.

It is a question of standpoint, of degree. So what is going on? One element may be personal. It may not suit Dr Cable's style to be too aggressive, to be too dictatorial. Another element may be party-based.

Perhaps the Liberal Democrats are intuitively more inclined to see both sides of an argument. However, there may also be a pragmatic element at play.

Future warnings

The SNP and Yes Scotland have repeatedly accused their opponents of scare-mongering. They have seized upon reports that one internal name for the Better Together campaign strategy is "Project Fear."

Perhaps, just perhaps, these complaints are beginning to register. Perhaps, just perhaps, those advocating the Union are concerned that raising repeated anxieties about independence may be a diminishing asset, that people in Scotland may start to discount such warnings. Heard it, seen it.

To be absolutely, ineluctably clear, this is not a transformation in the Unionist campaign. There will be more, many more, warnings about the proclaimed perils of independence.

Given that the UK's supporters are primarily countering a single proposition from their opponents, that is inevitable.